Helsinki’s sprawling underground tunnel network offers shelter from Russia’s potential threat – ABC News (Australian Broadcasting Corporation)
http://mobile.abc.net.au/news/2018-07-22/helsinki-underground-tunnel-system-shelter-from-russian-threat/10022486?pfmredir=sm Finland underground: Beneath Helsinki’s surface lies nearly 500 separate underground facilities and 300 kilometres of tunnels that snake their way throughout the city. Since the 1960s the city has excavated nearly 9 million cubic metres of that tough granite. Most of the areas are for public use, and include car parks, railway tunnels, wastewater →